High-resolution Ceres Survey atlas derived from Dawn FC images.

Kurzfassung

Introduction: NASA’s Dawn spacecraft was or-biting the dwarf planet Ceres in June 2015 in Survey orbit with an altitude of about 4,400 km to characterize for instance the geology, topography, and shape, of Ceres before it will be transferred to lower orbits. One of the major goals of the mission is a global mapping of Ceres. Data: The Dawn mission is equipped with a fram-ing camera (FC). The framing camera took about 900 clear filter images with a resolution of about 400 m/pixel and different viewing angles and different illumination conditions. Data Processing: The first step of the processing chain towards the cartographic products is to ortho-rectify the images to the proper scale and map projec-tion type. This process requires detailed information of the Dawn orbit and attitude data and of the topography of the target. Both, improved orientation and high-resolution shape models are provided by stereo processing of the Survey dataset. Ceres' Survey shape model is used for the calculation of the ray intersection points while the map projection itself will be done onto a reference sphere for Ceres. The final step is the controlled mosaicking of all nadir images to a global mosaic of Ceres, the so called basemap. Ceres map tiles: The Ceres atlas will be produced in a scale of 1:2,000,000 and will consist of 3 tiles that conform to the subdivision of the synoptic quadrangle scheme proposed by Greeley and Batson. A map scale of 1:2,000,000 guarantees a mapping at the highest available Dawn resolution in Survey. Nomenclature: The Dawn team proposed to the International Astronomical Union (IAU) to use the names of gods and goddesses of agriculture and vege-tation from world mythology as names for the craters. This proposal was accepted by the IAU and the team proposed names for geological features to the IAU based on the Survey mosaic. These feature names will be applied to the map tiles.